Patent GB-600575-A (GB)
Title: Method of preparing and treating plastic fabrications
IPC: A61L15/07
Filed: 1945-04-11
Abstract: A fabric made of or containing threads of a cellulose derivative, synthetic resin, or similar plastic substance is subjected to the action of a liquid which has a slight solvent action on the plastic substance, its saturation value for the plastic being less than 300 milligrams per 100 cubic centimetres of the liquid at 70 DEG  F., and the solvent is subsequently removed so as to produce a rigid material suitable for use as a surgical splint or cast or for use in making draperies, millinery articles, advertising forms, protective wrappers, boxes, baskets, furniture parts, screens, tents, trellises, or dressmaker's forms.  The fabric, moistened with the liquid of restricted solvent action may be formed into the desired shape and then set by removal of the liquid.  The fabric may be in the form of an open weave mesh fabric or a knitted fabric.  The plastic threads may be of cellulose acetate, nitrate, aceto-butyrate, or acetopropionate, or of ethyl cellulose, polystyrene, or other polyvinyl resin. Inert threads or fibres may be associated with the plastic threads.  The presence of these fibres controls or limits the shrinkage of the fabric when the solvent is removed.  The fabric may be used in strip or tubular form.  Fabric of matted fibres may be used and it may be provided with supporting threads or a porous flexible container such as a bag.  When the fabric is to be used as a surgical splint, it is preferable to pretreat it so as to control or eliminate shrinkage when it is subsequently applied to an injured limb.  Heating, or treatment with a shrinking liquid may be employed for the pretreatment.  The liquid used for the stiffening treatment may be a solvent such as ethyl acetate, a diluted solvent such as a mixture of acetone and petroleum ether, a mixture of two non-solvents which together form a solvent such as a mixture of chloroform and ethyl alcohol, or any of these solvents which contain the plastic material in solution.  In the case of cellulose acetate fabric, a solution containing not more than 86.5 per cent of acetone in water may be used.  For the pretreatment a more dilute solution of solvent may be used or the fabric may be heated.  Shrinkage during the pretreatment may be assisted mechanically by feeding the fabric to the immersion bath or heating chamber at a slightly greater speed than the forwarding rollers or conveyer belts and take-up rollers. Suitable apparatus is described (see Group VIII).  The pretreated fabric may then be applied to an injured limb (see Group VI).ALSO:A fabric made of or containing threads of a cellulose derivative, synthetic resin, or similar plastic substance is subjected to the action of a liquid which has a slight solvent action on the plastic substance, its saturation value for the plastic being less than 300 milligrams per 100 cubic centimetres of the liquid at 70 DEG  F., and the solvent is subsequently removed so as to produce a rigid material suitable for use as a surgical splint or cast or for use in making draperies, millinery articles, advertising forms, protective wrappers, boxes, baskets, furniture parts, screens, tents, trellises, or dressmaker's forms.  The fabric, moistened with the liquid of restricted solvent action may be formed into the desired shape and then set by removal of the liquid.  The fabric may be in the form of an open weave mesh fabric or a knitted fabric.  The plastic threads may be of cellulose acetate, nitrate, aceto-butyrate, or aceto-propionate, or of ethyl cellulose, polystyrene, or other polyvinyl resin. Inert threads or fibres may be associated with the plastic threads.  As inert fibres, there may be used cotton, regenerated cellulose, glass, metal or nylon.  The presence of these fibres controls or limits the shrinkage of the fabric when the solvent is removed.  The fabric may be used in strip or tubular form. Fabric of matted fibres may be used and it may be provided with supporting threads or a porous flexible container such as a bag. When the fabric is to be used as a surgical splint, it is preferable to pretreat it so as to control or eliminate shrinkage when it is subsequently applied to an injured limb.  Heating, or treatment with a shrinking liquid may be employed for the pretreatment.  The liquid used for the stiffening treatment may be a solvent such as ethyl acetate, a diluted solvent such as a mixture of acetone and petroleum ether, a mixture of two non-solvents which together form a solvent such as a mixture of chloroform and ethyl alcohol, or any of these solvents which contain the plastic material in solution.  For the pretreatment, a more dilute solution of solvent may be used or the fabric may be heated.  Shrinkage during the pretreatment may be assisted mechanically by feeding the fabric to the immersion bath or heating chamber at a slightly greater speed than the forwarding rollers or conveyer belts and take-up rollers.  Suitable apparatus is described (see Group VIII).  The pretreated fabric may then be applied to an injured limb (see Group VI).